The invention relates to the field of medicine and may be employed as a geroprotective substance for the prevention of premature ageing of the organism.
It is known that some of the main mechanisms of the organism ageing are: an increase in molecular lesions caused by free radicals, functional disturbances of the anti-oxidation defence system, and disorder in physiological functions of the epiphysis (1, 2, 3).
Since the claimed tetrapeptide, according to the invention, displays biological activity, and namely, geroprotective activity, a group of compounds possessing anti-oxidation properties must be referred to as analogues in application. Ionol food-supplement (2.6-di-tert-butyl4-methylphenol), being a well-known inhibitor of radical processes, has promoted an increase in the life span of LAF1 strain in mice characterised by accelerated ageing (4). However, the pharmaceutical based on 2.6-di-tert-butyl-4-methylphenol (dibunol) is manufactured in the form of a liniment and is largely applied in urology practice for treatment of cancer patients (5). Addition of ethoxyhin anti-oxidant (santohin) to food extended the life span of mice of C3H strain (6). An increase in the life span of experimental animals is also promoted by 2-ethyl-6-methyl-3-oxypyridine chlorhydrate, a low-toxic water-soluble anti-oxidant, which is a structural analogue of vitamin B6 (7, 8). An insignificant extension in the life span of experimental animals was facilitated by 2-mercaptoethanolamine, butyl hydroxytoluol, cystein, 3-hydroxypyridine, centrophenoxyn, lactic and gluconic acids, and glutathione (9, 10). Still, these compounds are not pharmaceutical preparations and they have found no employment in medicine as geroprotective substances. Administration of vitamins A, C, E resulted in an increase in the life span of experimental animals as well (11, 12, 13). Supersaturation of the organism with these vitamins, however, can unfavourably influence the functions of organs and systems and entail an intensive development of hypervitaminosis. xcex2-catechol, a preparation whose composition is formed by vitamins and vegetable substances, is known to display anti-oxidation activity (14). Administration of this preparation to SAM-P8 strain mice showing accelerated ageing augmented the survival rate of the animals. However, the mechanisms of its geroprotective action have not been studied enough yet, thus limiting its integration with clinical practice. After the mice of SAM strain, disposed to accelerated ageing, had been kept on a diet with an increased amount of carnosine (xcex2-Ala-His) for 7 months, their death rat decreased (15).
Still, carnosine is not a pharmaceutical preparation, its geroprotective properties being not studied enough yet. A minor increase in the average life span of mice was affected by the application of melatonin, an epiphyseal hormone (16). The impact of melatonin is associated with its anti-oxidation property (17). Nevertheless, the melatonin exposure of Drosophila melanogaster selected for a high embryonic mortality rate (HEM strain), failed to produce a geroprotective effect, though it was accompanied by an anti-oxidation one. Melatonin is not a pharmaceutical preparation and is manufactured in the form of a biologically active food additive.
Gerovital, a Novocain-containing drug, is used as a geroprotective substance. The detriments of this preparation consist in its possible negative influence on the functions of the cardiovascular system, its allergic impact, sometimes sleep impairment, feeling of anxiety, muscular and articular pains.
The claimed invention is aimed at obtaining a new biologically active compound of peptide origin capable of geroprotective activity.
The claimed peptide compoundxe2x80x94tetrapeptidexe2x80x94has no structural analogues.
According to the invention, there is claimed tetrapeptide L-alanyl-L-glutamyl-L-aspartyl-glycine of the general formula L-Ala-L-Glu-L-Asp-Gly (SEQ ID NO: 1).
With respect to the invention, the tetrapeptide L-alanyl-L-glutamyl-L-aspartyl-glycine with the following amino acid sequence: L-Ala-L-Glu-L-Asp-Gly (SEQ ID NO: 1) reveals biological activity, namely, geroprotective activity due to the stimulation of indices of the anti-oxidation defence system and due to the process of melatonin synthesis in structures of the diffuse neuroendocrine system.
The tetrapeptide is obtained by a classical method of peptide synthesis in a solution (19).
The geroprotective activity of L-Ala-L-Glu-L-Asp-Gly tetrapeptide (SEQ ID NO: 1) was stated in experimental trials. The study of geroprotective activity was conducted in Drosophila melanogaster by analysing the indices of anti-oxidation defence, life span, and the length of reproduction period, as well as in rats by examining the synthesis of extra-pineal melatonin.
With respect to the invention, the pharmacological substance capable of geroprotective activity includes as its active base an effective amount of tetrapeptide of the formula L-alanyl-L-glutamyl-L-aspartyl-glycine (L-Ala-L-Glu-L-Asp-Gly) (SEQ ID NO: 1) or its salts.
With respect to the invention, the pharmacological substance capable of geroprotective activity may contain salts of the amino group (acetate, hydrochloride, and oxalate) or of carboxyl groups (the salts of metalsxe2x80x94Sodium, Potassium, Calcium, Lithium, Zinc, Magnesium, and other organic and inorganic cationsxe2x80x94ammonium, triethylammonium).
With respect to the invention, the pharmacological substance is meant for parenteral, intranasal, oral administration, or local application.
The claimed pharmacological substance displaying geroprotective activity is capable of stimulating the indices of the anti-oxidation defence system and the processes of melatonin synthesis in structures of the diffuse neuroendocrine system, which, in their turn, inhibit ageing processes and promote a life span increase.
The notion xe2x80x9cgeroprotective substancexe2x80x9d, used in this application, implies the substance, which inhibits ageing and prolongs life by means of preventing premature ageing, which needs stimulation of the anti-oxidation defence system and the regulatory influence on metabolic processes in structures of the diffuse neuroendocrine system.
The notion xe2x80x9cpharmacological substancexe2x80x9d, used in this application, implies the employment of any drug form containing the tetrapeptide or its salts, which can be used for prophylactic and/or therapeutic purposes in medicine as a geroprotective substance in premature ageing.
The notion xe2x80x9ceffective amountxe2x80x9d, used in this application, implies the employment of such an amount of the active base, which, in compliance with its quantitative indices of activity and toxicity, as well as with respect to the knowledge available, must be effective in this drug form.
The notion xe2x80x9cpharmaceutical compositionxe2x80x9d, used in this application, implies various drug forms of the preparation.
In order to obtain pharmaceutical compositions, in accordance with the invention, the proposed tetrapeptide or its pharmaceutically applicable derivatives are mixed as an active ingredient and a pharmaceutical carrier in accordance with the methods of compounding accepted in pharmaceutics.
The carrier can have various forms, which depend on the drug form of the preparation desirable for administration, for example: parenteral, intranasal, or oral.
All known pharmacological components can be used for the preparation of compositions in doses preferable for oral administration.
For parenteral (intranasal) administration, the carrier usually includes sterile water, although there can be included other ingredients instrumental for stability or maintaining sterility.
In accordance with the invention, the method embraces the prophylactic or therapeutic exposure of patients to the claimed pharmacological substance in doses of 0.01 to 100 xcexcg/kg of the body weight, at least once a day during a period necessary for achieving a therapeutic effectxe2x80x9410 to 40 days depending on the character and severity of a pathologic process.
In accordance with the invention, the tetrapeptide is active when administered in doses of 0.01 to 100 xcexcg/kg of the body weight, although lower (higher) doses can be used as well, depending on the character and severity of a pathologic process.
The invention is illustrated by an example of synthesis of the tetrapeptide, whose formula is L-alanyl-L-glutamyl-L-aspartyl-glycine (L-Ala-L-Glu-L-Asp-Gly) (SEQ ID NO: 1) (Example 1), by the examples of tests for toxicity and biological activity of the tetrapeptide (Examples 2-8), and also by examples which show the results of clinical application of the tetrapeptide, thus demonstrating its pharmacological properties and attesting the possibility of achieving a prophylactic and/or therapeutic effect (Examples 9, 10).